584 GEOLOGY OF OLD HAMPSHIRE COUNTY, MASS. 



which the coarser sands (3) were deposited, and the eastern dip in these 

 indicates also that the cim-ent continued to flow eastward, or toward the 

 center of the lake. 



THE HADLEY LAKE DRAINAGE. 

 THE LEVERETT LAKE AND THE NOTCH EAST OF MOUNT TOBY. 



The last of the considerable deposits (m t) at high level on the eastern 

 side of the valley dependent upon the obstructed di-ainage which attended 

 the retreat of the ice occupies the long, narrow valley along the west border 

 of the Belchertown quadrangle, which runs north by the village of Leverett, 

 along Pond Brook, and past the entrance to "Rattlesnake Gutter," and 

 extends south across the town line into Shutesbury, skirting Mount Boreas 

 on the east and ending just south of this mountain, where, south of 42° 25', 

 the north branch of Fort Eiver, which occupies the lake's fonner outlet, 

 passes into a canyon to reach the open valley above East Street village, in 

 Amherst. This lake was early filled with sands, and the waters carried 

 their surplus into the valley, contributing to form the abnormally abundant 

 sands of the high ten-ace of the main valley a mile north of East Street 

 village. One follows the heavy sands from Boreas northward, filling the 

 valley clear across, until, just on the Leverett line, they are carried away 

 entirely by Roaring Brook, which comes out of the mountains on the east 

 and has worn out a deep circular basin in the lake deposits, cutting them 

 clear across, and escapes through a deep, narrow transverse valley into the 

 valley of the Connecticut. The high lake beds extend a little way down 

 this valley and stop abruptly, and it is clear that the lake could have 

 existed only so long as the ice remained to dam this outlet. Two miles 

 north of Leverett Center and opposite Rattlesnake Gutter, there is a passage 

 connecting it with the deep valley which runs down the east side of Mount 

 Toby, and by which the waters which entered this latter valley were 

 diverted into the Leverett Lake. 



The lay of the beds in this Mount Toby Valley is very peculiar and 

 interesting; a deep water-cut canyon runs the whole length of the valley 

 between the conglomerate and the crystalline rocks, and as a brook runs 

 south in its southern part and another north in its northern portion, while 

 its center is without flowing water, it is clear that it was not formed by 

 the present streams. 



